The present invention relates to a printer, and, more particularly, to a printer adapted to feed a continuous fan-folded paper web into the printer from the bottom thereof, wherein the initial loading of the paper web is greatly facilitated.
A printer of the impact dot type, the non-impact dot type and the like used as a print output device in various types of computers, word processors and the like has in general a friction roller mechanism for feeding each cut sheet and a pin-tractor mechanism for feeding a continuous paper web having series of perforations at each side edge thereof.
The supply of the perforated continuous paper web is in general effected from the rear side of the housing of the printer as shown in FIG. 3. In FIG. 3 the stack PS of the continuous perforated fan-folded paper web P is located at the rear side of the housing 100 of the printer. The paper web P is formed with a series of perforations PH at each side edge thereof, and the paper web P is guided around a platen 101 cooperating with a printing head 102 by means of a friction roller 103. The paper web P is fed by means of a pin-tractor mechanism out of the printer through a feed-out opening 104 formed at the top of the printer after printing on the paper web P is effected by the printing head 102 in cooperation with the platen 101 in the manner well known in the art. The pin-tractor mechanism comprises a pair of pin-tractors 105 located at the rear side of the paper web P at each side edge thereof adjacent to the feed-out opening 104 of the printer.
Each of the pin-tractors 105 comprises an endless pin-belt formed with a series of pins 107 thereon adapted to engage with the perforations PH of the paper web P and located in a tractor frame 106 so that the paper web P is fed when the pin-belt is driven by driving means (not shown). In order to permit the perforations PH of the paper web P to engage with the pins 107 and securely held in engagement therewith, a swingable guide plate 106a is swingably hinged to the tractor frame 106 at the front side of the paper web P so that, when the guide plate 106a is swung apart from the tractor frame 106, the paper web P can be loaded in the tractor frame 106 with the perforations PH thereof engaged with the pins 107, while, when the guide plate 106a is swung to its closed position after the pins 107 are engaged with the perforations PH, the engagement of the pins 107 with the perforations PH can be securely maintained during the time the paper web P is fed by the pin-tractors 105.
In such a printer, an additional space is required at the rear side of the printer resulting in disadvantage in saving the space, even though the loading of the paper web P into the printer is made relatively easy by virtue of the friction roller 103. Further, when a paper web P to which pieces of paper such as tickets are attached is used, the pieces of paper sticking to the paper web P tend to be stripped off when the paper web P is moved around the platen 101 at the deflection angle of about 180.degree.. Therefore, it is preferable to make the deflection angle of the paper web P around the platen 101 to be as small as possible.
In order to avoid the above disadvantages, a printer has been proposed in which the stack PS of the paper web P is arranged beneath the printer and paper web P is fed into the printer through a feed-in opening 108 provided at the bottom of the printer as shown in FIG. 4, thereby permitting the space required for the stack PS to be reduced to the minimum while the deflection angle of the paper web P around the platen 101 is greatly reduced.
In such a printer, however, the loading of the paper web P in the printer is made extremely difficult, because the operator must squat and look upwardly at the printer for loading the paper web P through the feed-in opening 108 and advancing between the platen 101 and the printing head 102 until the paper web P is engaged with the pin-tractor mechanism. Such an operation is extremely troublesome.